SharePoint list threshold Issue

Calling all SharePoint gurus! I am helping a client whose Kentico website cannot process workflows due to SharePoint list threshold errors. I have a pretty good idea of what needs to be done to fix this, but when I try to make changes, I get the same error message. I need someone to work with me quickly for a few hours to get this debugged. If we work together well, there is a good chance of more work in the future if you are interested!

Thanks,