I want to make changes to a presentation created or saved as a PDF file. I would like to delete some of the slides then email out.
I agree with Jan and Hovsep. Was going to suggest PFFill Tools Free myself!
Use PDFSam To Easily Split, Merge, & Reorder PDF Pages
under visual reorder there is delete button
Split, Extract, Reorder or Delete PDF pages from a PDF file into a new file.
You can use a free PDF editor to delete/move entire pages of the PDF file, for example PDF24
If you want to change actual content e.g. a text or images on the page you will not be happy with any PDF editing program out there. PDFs are simply not meant to be altered in that way.
The only tool I know of giving you full control/editing would be Adobe Illustrator. It can open/import a PDF file and then you can modify all contents to your liking and finally export it to PDF again.