Rotate as a weapon in UE4

Hello community’m creating a FPS project by EU 4 version 4.11 using as a basis for building the FPS which now comes standard with the graphics engine, and I have several maps and a lot of things I learned a lot but I have the following problem in the folder contained within the graphics engine and entered the sub folder weapons in there and changed the default weapon blueprint called for the gun Darkness WeapGun AssaultRifle weapons package Dark Sci Fi weapons (https://www.unrealengine.com / marketplace / sci-fi-weapons-dark), what happens is that when I change the Darkness AssaultRifle this is attached to the character and as seen in the image to the left.
My question is how can rotate the gun Darkness Assault rifle and put it in position correctly?
I hope you can help me as revised and can not find how to do it but when I change the default weapon looks good and in perfect position in advance thank you very much.