This is called prescriptive solutions.
Hip roof rafter repair.
Use a circular saw to cut two sets of new rafters from the same size wood by the same dimensions.
However it is important to fix the rafters before doing any other work to the roof.
Screw the new rafter into place.
Very easy to do.
The first step is to find out how many rafters are sagging and if anything else is damaged.
Sometime we just need a longer piece of wood like a hip king rafter.
Repeat the process for the joist beneath your old roof rafter.
Of course we re talking about splicing a joist or rafter as part of a repair technique for a rotted termite damaged or over spanned joist.
Fit the rafter into place between the boards and screw through the sister boards into the rafter.
This video shows how to repair a split rafter.
With the proper tools anyone can do this.
The fact is that there are many things carpenters do that are allowed because we all know they work.
If you are replacing the entire rafter screw down into the wood through the top and bottom joists.
You may find that several are in need of straightening and that some of the sheathing must be replaced.