Pretty simple to do, they are right under the pan.
Solenoids often fail due to debris getting caught in them, so you should consider pulling the whole valve body and cleaning it, then put a new filter and fresh fluid in. Dont' forget to drain the tq converter and flush out the cooler lines as well.
That will help prevent the new ones from failing. Would be a good time to install the updated rubber accumulators as well.
Jeramie