Increase Frame Rate using Twixtor in Vegas Pro 10

Can someone supply the steps to increasing the frame rate for a video clip while keeping the same speed. For example if I want increase a 1 minute long clip from 30fps to 60fps but keep it 1 minute at the same speed.

I've been looking for-ever to find the steps or a tutorial on this and haven't found one...at least for Twixtor in Vegas Pro 10.

Please help!!!!

FYI my experience level is I can slow a clip down using Twixtor and anything beyond that will be new to me, so details are a huge help:)

Thanks!

Adam