This pdf gives a detailed step-by-step set of procedures to correct this issue:
http://rick.sparber.org/ttya.pdf
If there’s no objections, I’d like to look into doing this.
Matt Zeits.
This sounds like a good idea, and if we have the mill apart to do this we should take this opportunity to clean & regrease the lead screw and ways.
If you are going to do this, I would like to be there (The mill is mine and is on semi-permanent loan to the hackerspace). What day works for you? In the near future, Thursday evening & Saturday day would work best for me, if some day next week works better let me know.
Also, this looks like it might be a fairly substantial operation. Looking over the PDF we will need to access some screws UNDER the X/Y table, which will require somehow lifting the mill off its table. Moving the mill into the hackerspace with two people was do-able, but had me doubting my sanity.
I wholeheartedly agree on you being there. That was my thoughts–I wasn’t going to proceed until someone reached out to you about this. Saturday may be good; I have to check my schedule. I think it would be wise to think out the access part of the operation well ahead of time. The only tools I have are a high lift jack at the moment, which is not a suitable lifting device for a 600lb machine. There’s no access from under the stand? That was the impression I got when I read how this guy was doing this.
Don’t be a wuss. We got my wave solder machine out out of there. 
Seriously, you probably could use a few hydraulic jacks combined with appropriately sized square iron tube to lift the thing. Or weld up a jig of sorts.
-D
I wish I had my 3 ton engine crane from new jersey. We could baby the head off of the mill and set it in a wooden pallet cradle and then work on the milling table alone. I guess wishing won’t get anything done though 
I can let you borrow a cherry picker that normally handles 500-1000lb engines if that would help. I’ll need to know in advance so I can arrange transport to/from.
-D