Watir xpath problem !!

[lote]

hi,

i have installed Ruby 1.8.2 version because i need ModalDialog
support.Only this version support modal dialog..and i've installed
watir 1.5.2 for same reason..so when i try to access element by xpath
using "ie.element_by_xpath('button[@id,'someid']').click, i have
error
message like this.


---> RuntimeError: Requires REXML version of at least 3.1.4. Actual:
3.1.2.1


Please tell me how can i upgrade REXML version to 3.1.4. i have read
some discussion about it but i could not find anything..


if you know answer,tell me step by step plz...


good work