You may have thought about increasing the number of stages in the Leads & Sales pipeline?
1. The 5 stages pipeline is fixed in number and you can't reduce or increase the number of stages. Our developers spent much time optimising the number of stages before making the pipeline live.
2. You can however edit the names of your stages by hovering over and then "click to edit this title".
3. If you only want to use 4 of the stages that's fine and then when you win the lead, just drag and drop it into Leads won from your 4th stage.
If you have further questions about this do a search on our support website and/or raise a support ticket to us.