It looks like your pictures were too big to go on the forums.  I've  re-sized them and added arrows, but it looks like you are on the right track. Disconnect the hose at the red arrow with the circle around it to add a T in. This is a good spot since the hose flexes and makes adding the T in easy.

Then return the oil to the back port with the arrow and circle. This port is below the oil level, so you'll want to pump the reservoir down below it. It would actually be a good time to change the hydraulic fluid and filter, as draining the filter also drains the reservoir.

Your loader control valve will need to be a closed center style. If it is going to be a permanent mount, I'd just run the hoses to it directly. If it comes off with the loader (quick attach) I'd put in a shut-off valve on the pressure line, and put quick couplers in the pressure and return line for easy removal. Just depends on what your set up is.