Good for you for wanting to help a friend like that. This is a pretty easy job, but I'd consider sending the heads to a shop for a valve grind and milling the heads (agreeing with Fairtax4me on this).
I've pulled my engine twice, once to rebuild after a spun rod bearing and the second when I found the Mech that decked the block put the alignment pins in the wrong spot causing head gasket oil leak.
Pulling the heads in the car never looked doable in my 2K wagon. People talk about it, but I don't know of anyone who has actually done this. I pulled the covers in the car and just doesn't seem like enough room to do anything useful there.
I highly recommend the factory service manual. Or maybe Strongly Advise...
To pull the engine, battery, washer tank, air box (to give you room to work). Remove air ducting. Remove the exhaust y pipe from the block (6 nuts), remove the engine mount nuts (two more nuts), remove the fans shroud and radiator, take the alternator out. Unbolt the AC compressor and power steering pump, leaving the hoses attached and move aside.
Remove the starter motor (and I made a bracket of sheet metal to keep the flywheel from turning - in the FS manual they show this 'tool' and it mounts into the hole where the starter motor came out of using one of the bolts or nuts from the starter motor to hold it in place). Remove the intake manifold by disconnecting the fuel lines and electrical connections (being careful to relieve the fuel pressure but you know this).
Use blocking under the transmission (or a floor jack) to hold it in place while the engine is removed. Unbolt the engine from the transmission (I think 4 bolts, an anti-pitch bracket at the top and two nuts at the bottom).
The long block should be mostly free - look for ground straps or anything else. I'm going from memory from about 3 years ago. At this point, if you have a strong back you can stand in the engine compartment and lift the long block out and set it on the radiator frame support, balancing it, step out of the engine compartment and carry the block into the house (that's what I did). I did weld up an engine stand out of rebar to keep from resting it on the oil pan.
I can pull the engine in less than two hours and I'm not a mechanic.
To turn the crank, I made a tool from a pipe with two bolts welded to it. One could do this also by drilling through at the correct spacing and place two bolts through with nuts to retain. Use the biggest bolts that will fit into the holes on the harmonic balancer. I spaced my to go into two adjacent holes so I could keep the crank from turning while removing the bolt on the balancer. No puller is needed for the balancer. This tool is necessary when installing the timing belt. Or go by the Subaru tool at no small expense. I like to fab up stuff from old bits if I can save a bunch of money doing it.
Last time I had the timing belt exposed was due to failing bearings in some of the idler pulleys. One was fine - the tensioner, but a little dry so I took the seal off and re-packed it. Been fine for over 30k miles so I'd call it good.
The only other tools I needed were common sockets (14mm, 17mm, 10mm, 12mm), ratchet, extensions. I did use plastic bag and paint marker system to label all parts, bolts, etc. Maybe not necessary now that I've done it a couple of times and recognize all the parts, but I'd advise it to anyone. I kept all parts in the back of the car so nothing would be misplaced in a garage.
I haven't looked here but I imagine there is a way to PM me. I might have some documentation to share from a 2k legacy. EJ25 engine specs should be all the same (block should have EJ25 cast into it), however there may be some minor differences as I have an EJ251 and don't know what that Forester has in it.