If you have the 8 speed trans, the OE pan and filter are 1 piece.
Quite a few members here have bought the PPE aluminum pan, which holds approx 1 extra quart of fluid, and has a replaceable filter.
OE Mopar fluid is pricey, about $20-ish per quart.
A garden sprayer, slightly modified, will serve you well for filling the fluid.
Quite a few members here have used Valvoline MaxLife fluid which is $25-ish per gallon, with great results, your call.
I did the OE fluid and OE pan on my '15. Ran me about $370 for the OE pan and 7qts. Mopar fluid from RockAuto. Just a drain and fill took about 5-1/2 qts.
It's been 50k miles since I did the drain and fill, and I wanted to do another to get more old fluid out, but have not done it as of yet.
Before you drain the fluid: Crack the fill plug loose first. Hercules put mine on, I had to use a cheater to break it loose.
Also use wet rags to help prevent burns from the exhaust.
You will have to raise the rear wheels about 10 inches to level the transmission pan rail, and you must finish the procedure before the trans reaches 122° F. VERY IMPORTANT.
@Wild one has posted FACTORY instructions from a new 8-speed copiously throughout this site. Follow them.
Rear diff. fluid change is a piece of cake. Drain, remove cover. Inspect. Clean sealing surfaces. apply new sealer. install cover, allow to cure. Fill.
Use the proper diff fluid with additive if you have limited slip. My '15 is 2wd is just a standard one, so 75W-140 with no additive was the one for me. Mine took about 2-3/4 qts.
I was nervous doing mine, but gained confidence because of the members here. You will be fine.