Hi whuzz
You need to be more specific here. You want to swap what type of Liteon drives exactly (Phat: 74850C, 83850C, 83850C, 93450C, 02510C / Slim: 9504, 0225, 0401, 0272, 1071, 1214)?
I suggest a lengthy read of the jungleflasher guide as it's all detailed in there with regard to drive spoofing. If they are the same revision liteon drives then no spoofing needed, just bring over your original DVD drive key to your replacement.
Cheers
Mark