How to take out the crown wheel and pinel in the front axle of a grand cherikee 2000 model

OK, I'm going to guess you are talking about the ring and pinion gears.
You need to remove both front axle shafts and remove the carrier to get the ring gear out. To remove the pinion, hold the yoke with a large pipe wrench and use a long wrench (for leverage) and remove the center bolt.
If you intend to re-build the differential you should know in advance you need a good dial indicator, a press to install side bearings, shim packs or crush collars, a good rebuild manual for specifications and experience in "reading" gear contact patterns.
Parts are expensive and if not assembled precisely they will self destruct very quickly.
Best option is to find a used "end to end" unit in a scrapyard, with the identical gear ratio. Replacement is faster and far easier than rebuilding, and less likely to fail.