You can use Migration Assistant but will need to connect the two Macs with a FireWire cable. Purchase an appropriate adapter first.
Migration from Mac OS X v10.4 computers to OS X Lion over your Wi-Fi or a wired network is not supported. However, if both Macs are equipped with a FireWire port, you can use Target Disk Mode to transfer your data:
- Verify that both Macs are equipped with a FireWire port. Note that different model Macs may have different FireWire connectors, which will require an appropriate cable, such as FireWire 400 to FireWire 800.
- On the Mac you want to transfer data from, Restart, and immediately hold the T key.
- Wait for the FireWire logo to appear on the screen. If it does not, restart and try again.
- Connect both Macs via the FireWire cable.
- On the Mac you want to transfer data to, Open the Migration Assistant application.
- Select the option "From another Mac, PC, Time Machine backup, or other disk" and click Continue.
- Select the option "From a Time Machine backup or other disk" and click Continue.
- Select your other Mac's volume, such as "Macintosh HD", from the list, and click Continue
Although the above information specifies Lion, it is applicable to your MBP running Mountain Lion.