How to add a disk to a new system without losing the data on it?

[Vincent Zee]

Hello,

How do I add a disk containing data to a new system without erasing 
that data.

I searched the mailinglist and the documentation but could not find 
information
for this scenario.

The system in question is running 4.8
The disk is coming from a 5.1 system and uses ufs with softupdates.
The disk has one partition.

/\
Vincent