There are two ways:
1. Save the (powerpoint) document as pdf.
2. Open the pdf, print.
3. Select the appropriate options in the poster option in the page size and handling section
4. The options are Tile scale: 200% for example, overlap by few tenth of the inches
5. Cutmarks and labels etc are optional #4 does the magic!
Another way that I learned from the internet is to paste the picture in the excel sheet. The excel is smart enough to segment the pic into multiple pages. And, I used to think that extra flowing line being printed into second page was a bad feature in excel! :)