Pasteles are too salty
The jury is still out (as far as I know) whether diced, raw potato in the water used to boil something like this will help draw out salt, but it's worth a shot. It won't help a lot, but it might help a little. You can then use the potato in another application.

Be sure not to salt the water you're boiling them in, and change the water if it gets salty.

Your best bet is to serve the pasteles with a sauce. Acid, a bit of sugar, and heat (as in peppers or cayenne) will all lower the sense you will get of the salt. Be sure not to salt (or at least seriously undersalt) the sauce!