Clean the from glass to remove all leftover OE adhesive using light abrasive like ScotchBrite

Clean the inside of the glass very well. This is your last chance and finger prints or dust on the inside will be there forever.

Clean the edges of the glass and mating surface on the housing with isopropyl alcohol.

Apply a very small bead of RTV sealant the entire way around the housing. Be sure there are no gaps in the bead. A syringe with a small dispensing needle is very helpful for this step

Place the front glass, be sure the it is right side up. Push down into place fully

Clean of excess RTV from the outside by wiping with isopropyl and a clean cloth.

Is you mess up or have any concerns about the amount of adhesive you used immediately remove the glass. Clean off all the uncured adhesive with IPA and repeat this step.