bounce n spin zebra HELP!

I bought my little man one of these from ebay for Christmas and it doesn't have any instructions. I've just put it up so I can check the condition - and cheer up my grumpy teething boy - and I've been left with 4 screws. I used 4 for the handle bars - where do these go? I assume on the bottom somewhere but can't work out where?

Sorry for the random post but am hoping someone here will know!