Those seal picks (Cdn Tire or Princess Auto) are useful for getting the seal spring and much of the bulk out, but will only get you so far with a baked on seal. I have a well worn, very cheap quality little slot screwdriver that I use for the next step as a chisel, run around by hand or lightly taped with a mallet. The aluminum alloy of the cheap screwdriver does minimal damage if I happen to get carried away. No great problem if you slightly damage the seal seat, you can use a suitable gasket sealer if needed. What matters most is not scratching or scuffing the shaft contact area. Well, that and not having too many seal fragments get into the block, but still not the end of the world if a little gets in. I’ll even use some fresh coarse steel wool (rock wool) to polish the seal seats, just being careful to wipe out stray fibres. Others may try to be more purist than that, but it’s really not all that critical as long as you get a nice clean seal on the shaft, even setting the seal in a little deeper if that gives you a better surface.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now