Request: Quick guide to migrate system drive

I'm running out of space on the system drive of a PMX3 installation, and I'd like to migrate it to a bigger drive. I have the new drive connected, and was looking for a quick guide on now to migrate everything to the new drive. I intend to remove the old drive, and boot from the new drive. (I'm not an expert with lvm so that's probably the piece I understand the least.. the rest seems easy).

Thanks in advance.