so you want to basically do 3 steps:
1.) base58decode the address
2.) remove last 4 Bytes (this is a checksum)
3.) remove first byte (this is network identifier)
There are many tools out there, but you didn't tell us, what operating system you use.
On
https://rosettacode.org/wiki/Bitcoin/address_validation are many different address validators, see if this fits your needs.
The bitcoin explorer provides as well a decode function:
https://github.com/libbitcoin/libbitcoin-explorer/wiki/bx-base58check-decodeAnd there was also a Perl version:
http://lenschulwitz.com/base58Not sure if a final tool exists, that picks up your somehow formatted list, and converts it, but with a little bit coding know-how, the links above will do :-)
