10.10 - How to reset lost user password on a guest on VMWare server?

I have a ubuntu 10.10 VMWare image that I set up a while back and have forgotten the login details. Normally I'd boot into single user mode to fix this, but I'm having trouble doing this on the vmware image. No grub screen comes up on boot, and attempts to hold down or press shift, space or escape during boot do nothing, the machine just boots up as before to the login prompt.

Any ideas?

As suggested by VMware KB 1004129, edit the virtual machine's configuration (.vmx) and add or edit this option:

bios.bootDelay = "15000"

This adds a 15 seconds delay to the initial BIOS POST screen, showing it for longer so you can press keys required to enter the GRUB menu.