To edit kernel parameters on grub-menu press 'e' (or TAB-key, if you run a live-mint): this will display your current setup in effect.
Replace 'quiet splash $vt_handoff' (search the according line ending with it) with your parameters.
When done press CTRL+X to accept the temporary modification and continue booting.
|nomodeset||turn off graphics-detection on boot = avoid black-screen|
|acpi=off||turn off power-management = is faulty on some machines|
The changes are not permanent = they will be gone on the next reboot.
Which is fine for most situations, as one does often use kernel-parameters to by-pass issues due to missing install of required drivers, or just wants to check if the param would help at all with some issue.
|IRC:bootgrub.htm||entering grub-menu on boot|
|IRC:grubedit.htm||making kernel params permanent|