I Did Mine In The Hot Summer Month's And I Think It All Came Out Cause I Let Them Drain For Like 30 Min.plus I Drove It About Ten Miles Befor I Drained Just To Help Heat The Fluid Up For Good Drainage.not Too Difficult Of A Job But If Not Carefull It Could Get Messy.make Sure You Put A Tube Of Lsd In The Rear Diff Befor Filling It Up With The Reg.oil.