About how long shud it take me I have a little experience and I just wanna know about how long? And shud I do anything but radiator replace and system flush

 

look in the OEM Cherokee section and search "cooling system flush" or "coolant flush" and you will see numerous threads on this topic and write-ups as well.

if you're replacing the radiator, you should replace both upper and lower hoses, thermostat ($10), water pump ($40), new gaskets for both, and possibly the serpentine belt as well. Even though that might seem overkill, since you're taking everything apart anyways, you might as well have the extra insurance of a properly working cooling system (b/c when one thing starts to fail, the others aren't too far behind).

 

I've got a spare 2-row in the garage with less than 5k miles woth of use on it.
$50 plus freight.