Shimano SPD cleat on LG ERGO Air?

Like the title says, I’ve got a pair of Louis Garneau ErGO Air with a 3 hex cleat

Can I stick a Shimano SPD cleat on it or better to just buy another shoe?

(looking for most cost effective method)

Forgive my limited knowledge in this area :S

I have what looks like a ‘triangle’ looking clip on it now for (road racing pedals)?

http://tenerife-training.net/Tenerife-News-Cycling-Blog/wp-content/uploads/2008/10/look-red-delta-traditional-cleat.jpg

and want the two little bolt ones

http://tenerife-training.net/Tenerife-News-Cycling-Blog/wp-content/uploads/2008/03/shimano-spd-cleats.jpg

You’ll have to remove the existing triangle cleat and install the SPD cleats. If the bolts don’t match up to the holes, you may need a new adapter plate inside the shoes, or they may not be compatible.