I would like to change this crankset to singlespeed, it has 96 BCD so I was thinking to order bash guard replacing the 40t chainring. The bashguard is this one http://www.wolftoothcomponents.com/products/96-bcd-bash-ring-for-shimano-compact-triple . Is it possible to remove the smallest 22t chainring to virtually have a single speed crankset? Thank you for your answers
Yes, it is possible. Just unscrew the bolts holding the smallest ring.
However, the chainrings in double and triple cranks are designed for easy shifting. With single chainring, it's a good idea to change the ring to one that has been designed to keep the chain on. So-called narrow wide chainring is one design to accomplish this.
That looks like it will work just fine. The bolt circles match. You can just leave off the small ring of the triple.
I did this conversion with the 9-speed triple Deore FC-M443. I used Saint FC-M810 CR81 (single chain ring plus bash ring). I just removed the original chain rings, put on the new chain ring and bash ring, leaving the smallest chain ring location empty. I had to file off some material from the inside of the Saint bash ring to make it fit on the Deore crank, but the bolt circles match (104 BCD) and it all attached securely.