Hi Dallasgal
The form you need is
IMM 1249 - Application to Change Conditions, Extend My Stay, or Remain in Canada found here
http://www.cic.gc.ca/english/information/applications/visitor.aspTick box "C" at the top, the fee is $150 for an Open Work Permit and as bundori noted, you should indicate that you only want it processed when your PR application reaches AIP. You do need to show proof of funds to support yourself and this can include assistance from your partner, not just funds you may have.
Hope this helps
Gdaymate