some tips –
It need to be warm, including the frame. As a rough guide you need to be combatable in a tee shirt. Having the frame helps a lot as well, it don’t need to be hot just kept in a warm room for a few hours first.
Use a 10:1 alcohol mix, be generous when spraying.
Clean the frame first, we use pure alcohol to do this.
Wear disposable gloves.
It need to be very clean where you do it, any dust in the air and you will get bits under the kit.
Not all the panels will stick down at the edges perfectly at first, you some time need to come back later and press them down.
Try and get the whole panel wet before fitting or you will end up with it dry sticking and it will be a different colour to the wet stuck parts.
Follow the instruction on the order of fitting the panels.
Mark off panels on the instruction as you go.
Check the orientation of the panel before you remove it from the backing.