Changing IRS outer joints on car

[undertow]

The rear outer spherical joints (both upper and lower) on my XR8 have seen better days and I'd like to change them without removing the arms if possible. Has anyone tried using a tool like the one below? I have read of people using these sucessfully on front lower ball joints. Do the rear joints come easily enough or is it a case of put it in a big hydraulic press and pray?

https://www.ebay.com.au/itm/10pc-Bal...4AAOSwf~Jaj9ai

I am not sure if this tool would be long enough or strong enough, but it would be useful to have anyway.