You can sell them at a car boot sale or use a number of online platforms including Gumtree, Friday-Ad, Facebook selling pages and other online platforms.
You can also give them away for free through Freegle.
RECYCLED Where?
If the board game is broken or there are pieces missing and it can not be repaired in any way then dismantle and recycle any cardboard and paper with your household recycling.
If there are components which might be useful to someone else then advertise them through Freegle.