Removing Channel Balances and Shoes

A home owner from Cambridge, MA says:
I have replacement double-hung windows, perhaps 20 years old, whose manufacturer I can't identity. The sashes are difficult to move; the lower sashes have trouble staying up. The windows seem to need new channel balances and shoes.

Your website is very helpful. But I don't see instructions that seem to fit removal of the channel balances of the sort on these windows. At the top of each channel, right above the channel balance, is a protruding, soft plastic rectangular block with wide flanges fitting into the channel. It seems difficult to remove without damage. There are no other visible attachments or hardware on the channel balances. The shoes are broken and detached and lie at the bottom of the channel. The channel balance is engraved with "E02 30 HD." Photos are attached.

Can you suggest how to remove these channel balances? After removal, perhaps I can deduce what sort of replacement of channel balance and shoe is needed.
User submitted photos of window hardware.
Profile picture of Tom
Tom from SWISCO responded:
Please see the video below. This should help you remove this kind of balance.
However, there is a possibility we won't be able to help replace your hardware. Looking at your pictures, your shoe appears similar to a discontinued part that we do not have. I can't be sure without seeing it out, but from the details I can see this appears to be the case.
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)