Do not connect the cable before doing those command because you can create a network storm (a loop and down your network)

Login to the switch with telnet

telnet ip_of_the_switch

type :

configure

Active the LACP

interface port_number lacp active

ie : interface 1 lacp active

setup the trunk

trunk port_number trunk_number mode

ie : trunk 1 trk1 lacp

Repeat those 2 last line for Each port in the same port

Do those command on both switches

Have Fun