1. Go to http://fishbattle.net and log in to your fish account.
**Note: your password must contain both letters and numbers to log in, change it in-game if it's not
2. Make sure you have enough points to purchase the item (you need 750)
2. Click on "Point Center" (2nd from the right on the top toolbar)
3. Click on "Purchase" on the ladder reset item (2nd from the top, leftmost button)
4. Click on "Purchase" (left button)
5. Click on "Item Deposit"
6. Click "Use" (left button)
(keep in mind that the picture above shows a different item, I didn't have enough points for the ladder reset item)
If you don't have 750 points to purchase the ladder reset item, it's okay. I'm pretty sure your points accumulate by just being active on the server. Just go ahead and either afk in the lobby, play melee games, or ladder as usual.