T-Mobile Prepaid Monthly4G plan with iPhone 4?

Hi so i unlocked my iphone and i want to use the prepaid tmobile 30$ monthly4g plan (100 min, unlimited text and web). How do i do this? Do i buy a sim from tmobile and put the activation code, sim card serial number, and my iphone imei? Will that option work? Please help. Thanks

P.S. I also went to walmart and they didn't have it(sold out) and i had to buy a phone with it.

Yes, this will work, but you will be limited to Edge (2G) speeds due to T-Mobile's 3G/4G frequencies not working on the iPhone.

Well I believe you should be able to but If you want unlimited everything for 49.99 Solavei which is like a prepaid plan uses the tmobile towers so same coverage and includes 4G… You will still have to get it unlocked but i can show youa website if you follow the link and chec it out… Solavei is a great deal oh and you can make money if you refer people to the company. Http://www.solavei.com/kyleetuttle