After removing the chassis and snapping out the interior, the glass is next. There are two spots where some light adhesive has been used. I just use a small flat tip screwdrivers and pry gently up.
Everyone has different methods for stripping.
I use %91 Alcohol. It is easy to acquire and inexpensive. Plus it won't harm the plastic.
I use an old case lid.
Fill to just over the top and cover it. Helps reduce the fumes (if that bothers you) and evaporation.
Around the 3 hour mark things start to soften.
Around the 4 hour mark I start to brush and clean away.
Yes these are actually decals. Scalextric has changed to this method a few years back. Once these are off, the paint quickly goes away.
Hope this helps.