You do an install from the dvd (not the livecd).
Proceed as normal to the disk drives to use in this install and make sure they are all checked.
Select custom partitioning scheme.
for /boot select sda1 partition and say edit. (select /boot as mount, ext3 as type, and check/select format
for swap - edit, type swap, no mnt point, format optional.
for / (root) same as #1 above.
for lvm (schroll up)- edit the vg, select the lv for /home at the bottom box, then click edit over to the right, select mnt as /home (no format)
for next lv (if any) same thing, just select the mnt point.
Then check the disk druid screen to make sure the the /mountpoints show correctly, and only the ext3 /boot, /root are to be formated.
proceed as usual.
Use the same hostname, users and passwords for best results.