Move DHCP from router to switch

[HunterAllenR]

We have a remote location with a router and two switches.

R1 <-> SW1 <-> SW2. 

SW1 was handling inter-VLAN routing and DHCP so the only traffic to the router was traffic going out to the WAN. SW1 failed and the inter-VLAN routing and DHCP was moved to the router as a short-term solution, which actually turned out to be a lot longer than planned.

What is the best way to move DHCP back to SW1 when it is replaced? Can the DHCP lease table be exported from R1 to SW1? Am I just going to have to have all the users reboot to pull fresh leases from SW1?

Any help to minimize the downtime would be greatly appreciated. 

[Reza Sharifi]

I think you want to make the change back to SW1 in a maintenance window, because right now the default gateways for your vlans are on the router and in order to bring them back to the SW1 you will need some downtime to delete the gateways on the router and add them to the switch. You can also move the DHCP at the same time.

HTH