It is a hard fight. I 3* that one by stun and ability locking the lead ewok.
7* sid
7* boba (AoE ability lock)
7* bane (stun)
5* daka (stun)
4* Vader (ability lock)
All max gear.
I couldn't do it until I brought in all the blockers and stunners. I was lucky enough to get a proc out of one each turn and was easy
Target the leader with daka or Vader and if they stun/lock him, switch targets and focus the other ewoks. If not then use banes and bobas to try, but once you get one or the other stop and see the specials for you next round of attacks.
Side note. Once I got past this fight. The others were easy.