You will need the system dis-charged before performing any work.
Loosen the belt
unplug the power
loosen the ac lines
remove the bolts
swap out the unit
put it back together and have the system re-charged.
Just to add to Marty’s post above, there are 3 10MM bolts holding the compressor. Loosen the back first and then the front 2. Also when putting it back in, make sure you have the bolts in the compressor holes especially the back bolt and lower front bolt. When you fill the compressor with oil, usually the new compressor comes with a cap on the 2 AC ports. I would fill and put it back on so when you are installing the compressor the oils doesn’t come out when you are maneuvering it. Good luck!