Converting Tridem to Tandem Wide Spread?

hello all,
Is their anyone with pointers or experiences removing a middle axle and pushing Rear forward?

We acquired a 2006 379 tridem,
I would like to convert to tandem with the widest allowable spread in Canada on 11r24.5's,1.85m (6ft) max for tandem axle spread.

Any input at all would be much appreciated!

Thanks