integration of older gdm

[Maaz]

I have to create a iso dvd image of SLES 10 SP 2 x864, that contains the gdm from SLES 10 SP1.

i.e please help me create the iso image of sles10-sp2 that contains gdm-2.8.0.7-57.29.x86_64.rpm instead of gdm-2.8.0.7-57.36.x86_64.rpm

I tried to do the above as
1, copied the sles10sp2x864 on filesystem as /sles10sp2
2, removed the gdm from /sles10/suse/x86_64
3, copied the gdm-2.8.0.7-57.29.x86_64.rpm from SP1 to /sles10sp2/suse/x86_64/
4, edit the /sles10sp2/suse/setup/desc/packages

changed the following
gdm = 2.8.0.7-57.36
as/with
gdm = 2.8.0.7-57.29

then made the iso with the following command
mkisofs -r -o sles10sp2x864.iso -J /sles10sp2

but when I tried to install via the sles10sp2x864.iso YaST/installer gives checksum error.

Please help
Regards