I cant promise the blazers rubbers are the same but look pretty typical and beive this way will work fine. If the seals are still pliable you usually can work and edge from the inside over the lip and push out the glass and seal while somebody outside the truck holds it to keep it from falling out. Put the rubber on the new window and in the deepest part of the seals edge that goes over the tops edge take something like a 1/8 slippery type nylon rope and lay the rope in the groove in the seals entire edge. leave some slack on each end of the rope,then with dish soap lube it up good. Set the galss and seal on the tops bottom edge as it will be when done and as somebody pushes from the outside snugly,slowly begin to pull the rope from one end only. This will feed the rubber over the tops edge and your done.
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