manual is telling me that the transmission is a sealed system for 3.8 engine on 2008 GC. Can i still change the fluid and filter or do i need to go to a shop?

I just changed the fluid in my 97 by unhooking the trans lines just the end at the radiator, putting them into a bucket, and cranking the engine for about 45-50 seconds, and using the engine to pump all the fluid out, then refilling the normal way. After re-hooking the lines that is.

You can change the filter & fluid yourself. Just be sure to use the proper trans. fluid. I think chrysler recomends an ATF+4 synthetic fluid in their auto transmissions now. Since there is no dipstick, just a filler tube, try to measure the exact amount that you removed. The way the dealer & trans. shop check the trans fluid is by inserting a probe down the dipstick tune & checking the fluid height by the temperature of the trans fluid. Things have gotten really complicated since the old days. Also there are no trans cooling lines going to the radiator. All cooling is done by a trans cooler mounted in front of the radiator. For a trans flush, i always go to Lee Myles. i have a Lee Myles shop nearby that i have total trust in. I had them do a flush first & 20k miles later i am doing the filter change myself..I have 2 2008 grand caravans & that is the trans maintenance i do on them . When you do a filter change, you only change out half the fluid. That's why i do a flush first. when you're ready to do the filter change later you only have 20k miles on the fluid. Never unhook a trans line & spin the engine over to try to get all the fluid out. That's how you take out the trans pump. You may get away with it once, but running the pump out of fluid already caused damage. When a trans shop does a fluid change they use new fluid to push out the old fluid always keeping the pump full of fluid. Hope this heilps.