Replace transmission cooler???

[Sasquatch]

Hello again guys!
So if I need my transmission cooler replaced, 1 can I do something like that without a shop and power tools, 2 if so, what, how do I go about it?, 3 if it's too big a job to do in a parking lot alone, how much should I expect a shop to want for that kind of a job??
Separate in Mississippi, coming off of a month of loss due to other breakdown issues.
Please help if you can....thanks