ZFS migrate data TrueNAS

I just ordered 6 16TB drives to upgrade my 8 4TB drives.

My server doesn't have any more room for expansion.

My Question is what is the best way to replace the 8 4TB drive with the new 6 16TB drives?

I was thinking of setting up a secondary server put the 6 16TB drives in that and copy the data over. Then just remove the 8 4TB pool and swap the drives around then add the 6 6TB pool.

However I am guessing this method might screw up my shares and settings I have on the existing pool.

Any ideas? Thanks