How the frak? 25 year old testor white putty...

Boy am i gonna catch some, issue: cleaning up/rebuilding and old NCC 1701-D built 25 years ago give or take a year.

Probleme, before i start i want to line all my duck in a row and attack this head on. The gaps were filled with testor gap filler and badly sanded.

How do i "soften/strip/remove this stuff?

I have taken ZERO steps so far just looking for some Tips. If pictures whould help i can upload them on my next post.

Thanks all

IMO, I would carefully sand and refill any gaps with new putty like Perfect Plastic Putty which is amazing. Polish out with finer grits, prime and repaint. If any scribing is to be done then use thick gap filling CA and accelerator then sand and polish. Using CA will be best for clean straight scribing.

Testors white putty could be thinned with their liquid cement, but I don’t know about old, hardened putty.