How to modify the line spacing in a field containing a bullet-list

Hi,
I am new to this platform and I am working in windows 10 and I am using the latest : Microsoft 365 version 2108.

In an Excel worksheet I merged a few cells with wrapping. I have put a bullet list in it by means of Alt + 0149 to make the bullit, then a line of text and [Hold] Alt + ENTER to go to the next line etc. etc. The wrapping is needed because some lines are too long. So far it is working fine! After putting all the lines of text in it I see that I have just too little space. I need the size of the text and the letter-type so I want to make the line spacing a little smaller. How can I do this in Excel?

Thanks,
Stoffie800, The Netherlands