SG300 LACP - Load balancing

So I can setup 2 Cisco SG300 switches for a small company. Each floor has their own Telecom closest which houses 3 switches and patch panels. On the ground floor, the main closest with the firewall, router and root switch is located. Since the cable run was done between floors, to avoid any cable damages and down time, a redundant cable was run. I want to implement port aggregation. I only know how to do so on Cisco catalyst.

My question is, how on the SG300 do I configure port aggregation and to not waste the cable, do I load balance between my distribution switch (second floor) and root switch(ground floor). All of the production switches are Cisco SG300.

Thanks!