Unfortunately I don't think it can be reversed like the M&P's.
Your manual doesn't show that it can be reversed either.
You may need to get used to using your trigger finger.
With practice you will get the hang of it.
As you can see from my username, I am a fan of this handgun.
Mine is a SW99c chambered in 9mm but is similar to the SW990L.
It's DA/SA and also has a decocker.
S&WForty has some good points but here are some others to consider.
Mag release paddles on the Walther lower vs. release button on...