what specific tool do i need to remove the freewheel pictured?

thanks

https://i53.tinypic.com/2kioo3.jpg

https://i53.tinypic.com/2dwewro.jpg

park fr1 or shimano compatible

Shimano spline is my guess .. since I don't see notches.

park tool 's fr -1 or shimano #40.

That's a 6-speed so probably an Ultraglide, not HG. FR-5 will NOT fit; I believe you need the older Shimano tool, I believe it's a TL-FW30, (QBP catalog number is TL2015).

pretty sure it is a mf-hg20. thought hg indicates hyperglide, no?

It says "MF-HG20", plus it's got an outside lockring, so it's a relatively new Hyperglide freewheel. It uses the same spline pattern as older Uniglide freewheels. They all use the standard Shimano TL-FW30 tool or the Park FR-1: https://www.parktool.com/product/freewheel-remover . A Park FR-5 is the same spline pattern, but it's made specifically for cassette lockrings.

Very old Shimano freewheels used a smaller diameter tool that's hard to find. Bike Tools Etc. sells the Bicycle Research version: https://www.biketoolsetc.com/index.cg...item_id=BR-CT4