It is easy to do.

The braided wire is better but I have used guitar strings, welding wire and hardware store steel wire. I have wrapped them around screwdrivers and wrenchs as handles but that kit above is the best and can be had for about $15 in many places.

They all work but the braided wire is best. As Challenger1 said it is strong and FLEXIBLE.

Here are some more tips.

I have found if you take a razor knife and trim as much of the sealant away from the glass & window channel as possible it is easier. The more sealant you have to cut through the harder it is to cut.

Cold glass breaks faster than hot glass. Do it inside or on a warm day if possible.

Never push on the glass to try to break it loose. If it seems to be sticking cut it again.

If you put it in crooked cut it out and start again. DO NOT THINK IT CAN JUST POP OUT AND RESEAT IT.

No wire cuts Urethane glue easily enough.

Use butyl or rubber gaskets on old school glass like ours. Urethane breaks down in sunlight. That is why all modern glass has black edges.

If you can find it use glass & Pinchweld primer for Butyl tape. It used to be common but not so much anymore.

Take your time.