decompile the esf cell model,
then decompile the brolly model,
import the brolly model's reference smd file, select everything but bones on the popup window
import the cell model, import the bones only,
now position and scale the model to fit the skeleton, 9which from the looks of things is borderline impossible, as that brolly is nowhere near the same stature as the cell)
assign the brolly's verts to that skeleton,
export that model over the cell reference file inthe folder where you decompiled the cell
now move all of the brolly texture's to that folder as well
compile the cell qc file,
this will grab all of the animation files texturs and rference files and place them all into one neat littile package that can be used ingame in esf, if it didnt work right, start over from the top
and thats the easy way >_>, the other way is simply to move the brolly dirctly over the cell ref file and remake the animations, (or rename the old ones) this can take a good bit longer