2000 grand am Radiator problem

I dont know what to do, my temp goes stright up when running for a fifteen mins, i have put coolent in and am thinking that i have to replace the radiator, i have noticed(when putting a cardboard box under car) that a little collent does leak but not a lot, I have no idea in what condition the radiator is in, looks kinda messed up, any ideas if this is somthing i can do myself? easy replace or more diffucult? and how much it will cost, either if i take it to a shop or do it myself. Thanks for any info.

Most likely culprit is a stuck closed thermostat.

Theres a few odd balls, but on most cars the upper radiator hose attaches to the thermostat housing.

Remove the housing & replace the T-stat.

A good T-stat is around 10 bucks at any parts store.

A Haynes manual for your car is around 20 bucks also at any parts store.