Tips on how to stretch?

[markglasco]

How do you seat the bead of the ff

275/40/17(eagle f1) on a 17x13,5
265/40/17(dunlop formula, stiff sidewall) on a 17x13

im fairly new to having 17 rims so im having quite a hard time making the beads sit!!

Things ive tried so far
-wet newspaper
-Bike tube.
-packing paper
-car tube

There is a shop here in manila that has a cheetah but they dont want to have anything to do with my rims, saying its not safe, tires wont bead, im just wasting their time, etc. they tried the cheetah once just to say that they tried but the technique was utter Sh*t so it failed. before i was able to stretch 195/50 on a 10" wide with no problems.

TL;DR
-i will be able to borrow a cheetah next week and i was just wondering what techniques you guys are using to bead these kind of tires?thanks in advance

*Outer lip is conical and the inner lip has a step lip.

My rims.

[markglasco]

I've heard of centering the tires on the rims, using a ratchet to squeeze the center of the tires so the sidewalls will stretch, using a head gun to soften sidewall and putting pieces of wood to stretch the side wall. i need as much info as i can get so please, feel free to add your own techniques!