I used bungee cords to strap the crib to the bed. You can get them at Home Depot, Walmart, etc. I also used one of the Jumbo Pool Noodles (the ones that are thicker than the normal ones) to fill the gap between the baby mattress and the side rail when I scooted the baby mattress over to the big mattress. I just used an old flat sheet to wrap (securely) around the pool noodle to keep it from being a teether. I bought mine at Walmart, but I'm sure that Target and other places probably have them too.
Re: tools /items needed to sidecar my crib?
this page has a video with instructions...
https://www.drmomma.org/2010/01/turn-your-crib-into-cosleeper.html
Little Rose is 2 1/2.
Here's how we did ours.
We used adjustable clamps like this...
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