Im stuck on the tigrex urgent quest in the guild. SOMEONE TELL ME HOW ..

Don't be scared to attack it when it charges let it run past you then attack it's back leg then roll either left or right depending which leg your on,use a thunder wepon which you can make from an iron katana it took me 6minutes 51seconds to kill the tigrex with a true devil slicer but just attack most of the time as it's not that hard

If you are finding it hard with melee weapon use a Bowgun

I used a Rockeater Heavy Bowgun, with 50 Wyrven Claws and 50 Small bone Husk to make Clust lv 2
Buy a shield for the bowgun.

If it's your first time go to area 8 to activate movie otherwise go to area 6 and if he isnt there wait for him on top of the ledge.
He always goes to area 6 when he sees you paint him first then let ripe with the Clust, you need the shield as sometimes if he throws snow at you from far away it may hit you.
Also if he screams next to the ledge he can hurt you abit so roll away when you see this.

He many leave but unless badly injured (limping) will always go back to area 6
If he goes to rest in area 3 either kill him by shooting Clust from the ledge above or Trap.

For a faster kill take a shock trap and bombs so when he goes to area 8 enter the area put down the shock trap and let him run into it. Otherwise just wait in area 6