Easy way to remove Lite Pipe from Hi-Viz sights?

I have a hi-viz dovetail sight on a Para Ordinance I just got. The light pipe is red and I prefer green. I tried to get it out, but broke off the flat end of the light pipe. The tube is stuck in the sight and it looks like somebody heated the pipe to stay in. Is there an easy way to get it out without ruining anything? And, if/when I get it out, is it just a matter of cutting the new lite pipe to size and heating up to stay in?