I have had mine out several times , what I do is work a cord around the rubber seal, the cord being 3/16 to 1/4 in diameter . Do this on the inside then spray some soapy water around it. start working on a lower corner gently pushing on the rubber and glass. You will be working the glass from the the inside out, working along the bottom side, doing this with hatch open so when glass is pushed out it is on top of tail gate. once removed take soapy water and clean out the groove with small tip screw driver amazing how much dirt gets in the groove of that rubber seal .
I have never used a sealant putting it back in and no leaks . When replacing said window put the rubber seal back on, now start cord at top outside corner working around the lower part of window back to the top of other corner. Put soapy water on it and slide top back in place with gate open , make sure the ends of the cords are on inside. Now start pressing on glass and pulling on cord the cord will pull the rubber back and allow it to go back in place. The reason I know this is I took my rear window out with a weed eater oops. I now have a spare glass and seal for next time.