Study the old original e-brake cable and note routing.
Hopefully it is the original and routed as OE designed.
I myself have never removed the whole front floor pan which also requires removing all the carpet and front seat let alone another 20 plus bolts and throttle linkage. Anyway....
At the hand brake handle there are two bolts that position and clamp the end of the cable housing to the hand brake handle assembly.
There is aslo a clevis pin with a cotter pin to remove at the hand brake lever.
Next thing to remove is a double screwed aluminum clamp ring retaining the rubber grommet and cable located at the upper drivers side of the firewall.
Then remove the E- brake cable clamp bolt at the lower steering column.
The e-brake cable is routed between the engine rear cross member and bell housing cover...stays close to the drivers side lower rubber engine mount.
Just rear of this cross member there is a cable end retaining clamp located on the transmission side cover...remove the bolt and nut...pull cable end out of this retaining clamp.
Under the car at the rear of the transmission remove the e-brake return spring, cable yoke clevis pin, also remove two nuts retaining the cable end "U" yoke....remove said yoke.
Remove cable assembly from car noting proper original routing.
Install the new cable in reverse order.
Adjust cable down at transmission brake band for proper e-brake operation.
A fun little project..not too difficult...a little tight up by the handle brake.?