I suggest to get an MG over HG. For an adult you should have no problem to comprehend the assembly. Get a good yet reasonably priced MG like Jesta.

Click Here.
Look at the bright side, all you need is a snowy background, some rocks and talc powder to make a winter diorama!

You can use high % of IP alcohol. Or RM 3 nail polish remover should work like a charm. Use Q tips to gent but firmly rub on surfaces with decal applied, and just use cloth on surfaces without decal applied.