How do I convert my 2wd wrangler to 4wd?

Not a practical undertaking to do so as it would be well beyond reasonable expenditures! .. It would be more cost effective just to trade for a 4x4 model... The large parts like: the transmission, transfer case, suspension, steering, differentials and remainder of the driveline components would be the easiest part of the job .. It's the small stuff that one doesn't consider that makes it so impractical like: the wiring, control modules, 4x4 controls, indicators in dash instrument cluster and a lot more that will show up as the project progresses... It is doable but you would need really deep pockets!