Decal softener will make them more pliable, but it also will melt them onto the model if you don't get them off right away. What I used to do was actually sand them down/off (with a miniature file or very, very light and small sand paper, the kind you get at hobby stores to smooth paint) as they were on raised areas and then painted the area (as it is usually note a highlight area) and started again with a new decal.

My two cents,