[Trisquel-users] GRUB not accepting password

[foocha]

I recently installed Trisquel on a fairly old laptop. In order to boot from  
the liveCD, I needed to add the boot parameters "acpi=off" and "nomodeset".  
However, now that Trisquel has been installed, I cannot add these parameters  
in GRUB. I looked up the randomly generated password, but when I enter it I  
am just redirected to GRUB, without the ability to edit anything. I can't add  
the boot parameters any other way, because I cannot get my laptop to boot  
past GRUB. I already tried commenting out the lines containing the password  
in the 01_PASSWORD file, but no luck, GRUB still asks for a password, and it  
doesn't accept my username's password either.
Any suggestions?