I cannot chime in on the M&W hand clutch as I have no experience, but the standard brake seals can be a little tricky, sometimes. Most methods I have seen without disassembling the transmission involve using sheet metal screws ran into the seal face in 3-4 locations to act as a 'puller'. Essentially, you drill a few small pilot holes in opposing corners, and use some long sheet metal screws to thread into the holes and push against the pinion carrier casing behind the seal. Tighten them gradually to pull evenly on the seal. The pinion shafts must be removed from the inside of the transmission, not the outside... So this method would require removal of the top cover.
Also, IF you are going to remove the top cover and remove the pinion shafts, you must remove the axles and bull gears prior to doing so. If you are going to go this far, you might as well check your bearings throughout (especially your inner axle bearings). From here, you can pull the pinion carriers and just drive the seals out from the inside to make life real easy on you (although it may have been a tough road to get this far).
Depending on how long the brake drums have been on the pinion shafts, they may slide right off, or they may require a large 2-jaw puller. My H's slid right off without issue.
I have a teardown series on a project I am currently working on (1942 Farmall H for Suicide Awareness)… It details nearly every step of tearing the transmission apart. The H and M are nearly identical, with the exception of your M&W hand clutch. Link is below for the transmission section (parts 1-3).