I have removed ceramic tile off about a 2000 sq ft floor. I am planning on putting vct down. I need a tip on removing all of the excess mortar on the floor. Please help

While I am not familiar with the term 'vct' I can offer an idea.

A tool rental shop might have a concrete cup grinder you can rent,I have used one to grind down heaving concrete which kept a commercial door from closing properly in the winter months.

They charge per cm of ware(or a flat rate sometimes too),no matter which way you do this it is going to be laborious.

KBC

The mortar is much softer than the concrete. An air powered chisel should easily remove the mortar. An electric hammer drill (which can be set to hammer only) would also work. Harbor Freight Tools has a 1" hammer drill that uses HILTI type bits. You can buy a 2" wide chisel there also which fits in the drill. It works like a charm.