Finally got my replacement insulated glass unit (fixed window) and have the trim pieces (vinyl window) off.

Figure I now need to cut the seal which I assume is a bead of silicon.

What works best, thin flexible putty knife?

Is one of those suction cup lifting handles worth while, I probably have a couple other windows that will be replaced in the future, this is my trainer!

 

A cup is nice, it gives you good control as you set the new glass back in on the rubber spacers. I like the Woods brand cups. Amazon has one in a yellow box that is reasonably priced. I've got 4, but I do a lot of windows, doors and glass.

As for the best way to cut the glazing, whether it's two faced tape or silicone, (you can usually see it from the inside if you have an eye for it) there are special tools made to do that. But in a pinch, Lowes has a nice flexible blade... can't find the replacement blade #, but it's the hooked linoleum style blade in this set.

It's flexible enough and thin enough to slip into the glazing, then you run it around the edge and cut the glazing. Also nice to have the cup out there with you to hang onto as you cut the glass free.

Amazon also sells the two faced tape... be sure you get the right size... 1/16"x 3/8" is most common. And get the tape with the poly backing (blue) not the paper backed tape.