You cannot delete LVs when they are active make any VG changes with active LVs.
Here are high level steps of what you could do after taking a backup
of your data:
1. Disable and remove swap (see here
2. Unmount and remove LV0 and LV1 from VG1 with umount/lvremove
3. Remove VG1 with vgremove
4. Unmount LV0 and LV1 from VG0 with umount
5. Extend VG0 with any available PVs if necessary
6. Mount LV0 and LV1 on VG0 with mount
7. Create and enable swap (see here
Note: You could also merge the VGs instead of step 3 above. Ofcourse you will have to unmount volumes in VG0 prior to doing that.
Basically you are left with VG0 which contains LV0 and LV1 .......
....or you could simply backup your data, rebuild the server to your liking and restore the data!