So I tried to single-handedly replace a slab of sidewalk last week.
Near killed my po' self, mixing and pouring, etc. Was so worried
about thunderstorms etc, I forgot to cut/set the expansion joints.
Forced 'em in as the 'crete was being finished. They stick up
as much as an inch above slab-level.

How do you cut this stuff? It is Quikrete 1/2 In. x 4 In. x 5 Ft.
Expansion Joint per Homey-Flogging-Depot:

http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053

Sez it is made from resilient cane fiber. Looks like cardboard
soaked in asphalt gunk. Tried cutting with utility knife, it sorta
shreds.

Best case would be if I could pull 'em out without making a hideous mess. Then
I could cut some wood joints to replace 'em. But they don't seem to wanna
come out.

Mea Culpa: I blew this part of the job. Any help much appreciated.

Will