Network design – doubt on advertising customer LAN

Hi All,

Following is my scenario for which I’ve doubt:

Site A — LAN 1 — L2 Switch1 — PE router port1 — MPLS — Site B
Site A — LAN 2 — L2 Switch2 — PE router port2 — MPLS — Site B
Site A — LAN 3 — L2 Switch1
Site A — LAN 4 — L2 Switch2

How can I advertise the LAN 3 and LAN 4 to Site B using existing devices?

Thanks for any help.

Regards
Britto Sidhan