is the gel not just a lubricant to assist sliding it into place?
when applying vinyl i use special squeegies that have felt along on edge and rubber on the other for smoothing down without scratching
is it vinyl? as it often stretches when you remove it so you can lose the shape, and adhesive can be left behind.
when i do big areas i use soapy water or glass cleaner to 'float them into place and then squeegie the fluid out and the heat them to bond them down...can make the difference between being permanent and lasting only a few days
saying that, you can buy liquid adhesive in a pump spray
short answer, yeah a little warmth such as a hairdrier, and use a very thin blade carefully to catch the edge to lift it..not your fingernails
