If you are just walking to Pelion you can head in along the Lees Paddock Track (Tasmap CATHEDRAL 4236 - 41 49.99'S 146 11.57'E). The track up from Lees Paddock takes a bit of finding, but basically you walk north from Lee's hut to a point where the creek meets the hill. There is a sign on a nearby tree.
You can also walk in on the
Arms River Track (Tasmap Rowallan 4237 - 4` 47 530'S 146 09.755'E). The first 100 meters in altitude is a reasonable walk, but the second 100 meters in altitude is very steep. That is the hardest part of the walk though. Once on-top it is a pleasant walk.
If you want to walk to the "Walls of Jerusalem" and then on to Pelion, then one choice is to walk back out the "Walls of Jerusalem Track" and then take the "Junction Lake" Track. This track starts about 750 meters above the Trapper's Hut.
See here.
I believe it is also possible to walk down the Jaffa Vale to lake Ball, and then walk out to the Junction Lake Track. I met a couple at Dixon-Kingdom Hut who had walked that way, but I have no knowledge of the conditions. I don't think there is a marked track, but I'm not sure.
Either way, once you are on the track, you follow it to Junction Lake. Then
referring here you will read that you can cross the Never-Never to pickup the overland track. There is not a recognized track through here, so you might need to get advice from those who have walked this route.