Having a problem... male refuses to breed now?

[redshepherd]

I read somewhere that if you have a second mature male, you can pop it and place the sperm plugs on the female's back. That can trigger the guy without having the second male in the enclosure.

I read that around too- I'd try it, but no idea how to pop them. I watched a video and tried it before, but it just didn't work and I'd prefer to avoid any risks hurting him.