What tool do I need to disassemble this 5 speed freewheel I have a 5 speed freewheel that I need to take of from hub, but the standard freewheel tool that I do have does not fit.

On the freewheel following text is engraved:

UC SHIMANO SIS
MF Z015 China

It seems to me that tool would need to have 12 splines.
I found a bunch of forum posts from people with similar problems. Shimano freewheels made prior to about 1985 have smaller diameters, about 20mm instead of 22-23mm that they have today.

A search for "Shimano freewheel remover 20mm" brings up some useful results. It looks like Bicycle Research Tools makes a remover called the CT-4 which is designed for older Shimano freeheels.

Good Luck!