Help regarding recovery of block.io wallet

I recently found out that the block.io online wallet was shut down. This left me with a recovery file that does not include a 12-word seed, only a number of private keys.

I tried recovering this wallet using Electrum, which led to no avail as it seems that the wallet generated by block.io is a "Multisig"? wallet. So instead of having a single private key, I have a pair of 2, and I can't for the life of me figure out how to recover my bitcoins using these.

In the recovery file provided by block.io it is clearly stated that they recommend using "Self-hosted Bitcoin Core ... to transact with your addresses". This led me to install Bitcoin Core (which took a damn while). But after downloading all the needed stuff I see no option to import one of these so called "Multisig" wallets.

This leads me to my question. Is there anybody active here who has any experience recovering a wallet like this? I'd greatly appreciate some tips to help me recover my bitcoins. Thank you in advance.

Here is the instruction provided by the block.io recovery file:

"General Usage: The data below provides you with everything you will need to use your addresses anywhere you deem fit. The addresses in your Block.io account are multi-signature addresses of the type P2SH, P2WSH-over-P2SH, or P2WSH. Each address requires two private keys. The first key is BIP32-derived, and the second key is fixed. You can use any BIP32 tools to determine private/public keys for your addresses at depth i, where 0 submitted by