Multi-Region a Proline 1100 and/or an Alba DVD74

Hi All

I've got a region 1 (US??) DVD that won't play on my Proline 1100 or Alba
DVD74 (both region 2 - UK??) players.

Do you know of a way I can unlock these players to make them play
multi-region DVDs?

I've tried

1. Open the disc tray.
2. Place disc on tray, but don't close.
3. Press 0, 1, 2 and 3 on your remote, one at a time
4. Press play. That's it: Multiregion.

for the proline, but it doesn't work.

Thanks

Laphan