How to delete no. elbow

Being at Branch level:  HOME TAB-->Delete-->CE Members

Or you can also select them on the 3D view keeping the CTRL key pressed and then clicking on Delete key on the keyboard

Dear sir,
3D view i can't find
so could please explain

3D view is where you have your 3d model displayed....tin he picture you have attached you have the explorer and the 3d view

Ok SIR,
TOMORROW I WILL TRRY AND WILL COME BACK

collect elbows using search and use Delete Elbow command in collection window

Ok sir

i will check 

Thanks