I have a multicraft minecraft server and i want to expand how many people can get on?

I have this multicraft server i bought for minecraft and it said unlimited slots ( slots is how many people can \get on my sevrer) and i don't know were to change it.

Trevor T

Go to the server folder (the one you created to put the downloaded server from Minecraft.net)
Go to server properties and scroll all the way down, change the number of people you want to get it