unfortunately this guide, as many other ones, doesn't explain anything if the seed was too long
I'm still waiting for a damned IOTA dev reply to this thread, maybe after 1 year or 2 I will find somebody helping me to recover my IOTA lost-in-sleeping balance
I have the 2.4.0 wallet running on two separate computers... The wallet on my main x58 i7 desktop runs slow, and I have connection issues, along with transactions not showing up until I restart the wallet.
The wallet running on my 9yo crappy c2d dell studio lappy runs the wallet much faster, and I don't have the connection problems, or transactions not showing up right away... Go figure.

Do you have another computer you can install the wallet on?