this is how i did it when i made unicornpup.
1 . visit
https://github.com/puppylinux-woof-CE/woof-CE click the download button , download the .zip & unzip.
2 . click on merge2out-gui and choose a pup (newer pups are more likely to work properly)
3. you will now have a woof-out folder for your pup.
4. in that folder is the DISTRO_PKG_SPECS file. this is the recipe for all the packages in that particular puppy. open it in geany and choose what packages to remove by simply changing yes| to no| at the start of the line. lots of packages are obvious like abiword & deadbeef.. so just start by saying no to the recognisable ones.
5. once done editing click on 'woof_gui' script
6. select 'download dbs' tab and click 'UPDATE LOCAL DB FILES' button
7. select 'Download pkgs' tab and click 'DOWNLOAD PACKAGES' button
8. select 'Build pkgs' tab and click 'CREATE PACKAGES'
9. select 'Build distro' tab and click 'BUILD DISTRO'
10. try booting your new pup
and then keep stripping by refining the DISTRO_PKG_SPECS . it will require some googling and some failures when you start removing libs.
my advise is just give it a go and see