Quoted from merccat:1/4” nut driver. Sockets tend to be too fat to fit in that area.
The trees are basically made from something kinda like dog squeaky toy material so it’s flexible but can tear so be careful.
Worst case I think they are reasonably priced if you need new ones.
I have one more set that have the led eyes that flicker with leaves and a glowing led emerald city package for sale check my back bread for pics if interested
https://pinside.com/pinball/forum/topic/the-wizard-of-oz-a-woz-journey-along-the-yellow-brick-road