How to replace evaporator ?

You need to replace it. I do not know of many successful repairs to aluminum evaporators.

found leak dye by evaporator coils. so ordered evaporator and replaced it.

P0496 is not alisted code.
P0455 - Evaporative Emission Control System Leak Detected Gross Leak (fuel vapors)
Symptoms - Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors Possible causes - Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking

That is a problem in the evaporative emission control system.
Could be anything causing it
Clogged filter in the charcoal canister
A leak in one of the vacuum lines
The purge valve not working,,,etc.
The best thing is to take it and have it checked out, they might have to do a smoke test to find the problem.
All they do is inject smoke into the system, if there is a leak the smoke will come out of it. All it takes is a pin hole in these emission systems to screw it all up.

P0446 Evaporative Emission System Vent Control Circuit.
The following are descriptions of all Evaporative possible codes:

P0441 Evaporative Emission System Incorrect Purge Flow
P0442 Evaporative Emission System Leak Detected (small leak)
P0443 Evaporative Emission System Purge Control Valve Circuit
P0444 Evaporative Emission System Purge Control Valve Circuit Open
P0445 Evaporative Emission System Purge Control Valve Circuit Shorted
P0446 Evaporative Emission System Vent Control Circuit
P0447 Evaporative Emission System Vent Control Circuit Open
P0448 Evaporative Emission System Vent Control Circuit Shorted
P0449 Evaporative Emission System Vent Valve/Solenoid Circuit
P0450 Evaporative Emission System Pressure Sensor/Switch
P0451 Evaporative Emission System Pressure Sensor/Switch Range/Performance
P0452 Evaporative Emission System Pressure Sensor/Switch Low
P0453 Evaporative Emission System Pressure Sensor/Switch High
P0454 Evaporative Emission System Pressure Sensor/Switch Intermittent
P0455 Evaporative Emission System Leak Detected (large leak)
P0456 Evaporative Emission System Leak Detected (very small leak)
P0457 Evaporative Emission System Leak Detected (fuel cap loose/off)
P0458 Evaporative Emission System Purge Control Valve Circuit Low
P0459 Evaporative Emission System Purge Control Valve Circuit High
---
At least the cap isn't loose for the gas tank.

I would clear the code with an OBD-II Scanner 'erase code' button, and see how long it takes for it to come back.

mcdevito75 here, Yes, or a good part of it. But wait, if there is water on the pass. side it may be the drain for the evaporator, in that case look under the evaporator and make sure the rubber drain hose is attached, also use something to un clog it. If it"s the evaporator leaking freon then you"ll have to remove and change or fix the leak, a radiator shop can seal the leaking evaporatoro once out of the car, first you"ll have to drain all the freon from the system.

you should have someone leak check the system with dye and gas sniffer. the most common problem with these jeeps is the evaporator leaking.

First of all, these codes are what are called "Powertrain Trouble Codes' (that's what the "P" means P=Powertrain). TCM Request (Transmission Control Module = TCM). The request was to turn on the 'Check Engine" light.
P0720 - output speed sensor circuit malfunction
P0715 - Input speed sensor (turbin speed) circuit malfunction
P0442 - Evaporative Emission System Leak (Small Leak)
P0455 - Evaporative Emission System Leak (Large Leak)
Check fuel filler cap problems - for Evap Emiss leaks
Replace the pulse generators & have the trans fluid replaced/flushed.
The Main Catalyst System Efficiency Bank 1 Is P0420, not P0442
If you had P0420 code, the catalytic converter is shot... and that's an expensive component.

MORE THAN LIKELY THAT REAR A/C EVAPORATOR IS LEAKING..FAIRLY COMMON..HAVE REPLACED MANY OF THESE ON THESE VEHICLES..

the dealer does not want problems with somthing they just fixed so they tend to replace more than needed to be on the safe side ask around and find a good local mom & pop shop they should treat you right