what prepaid u plan to get

if hotlink then easier
u can do it from website.
no need use dialer

Root - use Nexus 7 toolkit : it is simple n straightforward. It is menu driven - as long as you know how to launch the program , just select n click only
Use it to install recovery too
Boot tablet to recovery mode and flash CM10 zip file from there ( select wipe caches n dalvik cache n wipe data first )
Use it and you will be ashamed to ask people to help you. It is so freaking easy that I always say is a no brainer tool , literary means no need brain also know how to use the toolkit
Just follow the guided instructions

Installing recovery ( CWM or TWRP) is a separate option in the toolkit - I remember is option 6