Yes, go ahead and change it. You probably don't have a drain plug, so you will have to remove the cover. You can buy a new gasket or use RTV sealer or whatever the stuff is called. Make sure you scrape the old gasket off well. You can check to see if you have a locker by finding the G80 code in the glovebox. I believe that it will take a synthetic 75w-90 either way though...no additive for the G80 if you do have one. It takes just short of 3 qts if I remember correctly. You will either need a bottle with the nozzle or a pump to get it in the fill hole.