Grace notes in timpani music aren’t overly common but they happen once in a while so you have to know what to do when you see them. The tendency might be to play them the same way that you’d play them on a snare drum, but that really wouldn’t sound the best.
Basically, great notes on timpani need to be played with more space between the notes and they are always played hand to hand.
Watch this video to see what I mean and then try it yourself
This note 
should be played by sticking left RIGHT or right LEFT with the main note louder than the grace note. However, there should be space between the grace note and the main note so that is sounds more like this: 
This double grace note 
should be played hand to hand either right left RIGHT or left right LEFT and should be played open to almost sound like this: 
When you play a triple grace note like this one
try to think sixteenth note or thirty second note triplets that look like this: 
and always play hand to hand: left right left RIGHT or right left right LEFT.
