Very simple, here is the command to convert man page of ls command to text file:

man ls | col -b > ls.txt

Then use lpr print command to print ls.txt file i.e. it sends a print job to the default system queue/printer connected to Linux/UNIX:
cat ls.txt | lpr
OR
lpr ls.txt

You can also try:
man ls | col -b | lpr

You can also print GNU Linux info pages:

info ls | col -b| lpr

Please note col command filter reverse line feeds from input i.e it removes \r \n like character.