Q: S3 using Monthly 4g $30 plan

[vince2398]

I just purchased a S3 on contract from TMO but would like to cancel the service, pay ETF I assumed and go onto the Monthly 4G $30 unlimited text, data 100 min plan. Has anyone done this before and can suggest how I can easily do this? Not sure if this works using the micro SIM card etc. Thanks in advance.