If you have adequate tools, replacing scales is not too hard. All you really need is a small belt sander, band saw or a simple scroll saw, drill, and lots of sandpaper.
Tempting to purchase supplies (handles, etc) from the larger knife supply retailers from the US. However, the shipping will kill you.
I recommend the following:
https://www.knifemaker.ca/
They have a decent inventory of handle materials, along with fasteners (ie. brass pins).
I recommend epoxy for securing scales to the metal. Lee Valley has excellent products, and free shipping if order is over $30.00. Gorilla 2 part epoxy will work, and available at CT.
One thing you need to remember: if you use hardwood, or some other composite, you may not be able to wash your kitchen knives in the dishwasher. Research that.
Lots of good YouTube tutorials available.
This is a fun project, Good Luck.