As the shop templates is based on the version zen cart v1302, I need to upgrade the shop version or try a method to install this addon on a older version. As it says only for zencart 1.3.9 and 1.5.x.

If I can not install it on the older version of zencart . How should I upgrade my current custom templates to fit 1.3.9h or 1.5.x?
Is there a "text book" with more details which can teach me to do this upgrade?

Online waiting for help!