convert calc to ubuntu from Windoze

I have some calc spreadsheets I have created in Libre office 4x ( Windoze 7). embeded in them are around 5000 hyperlinks which when you click on them bring up for example a local file C:\users\tim\sample.pdf
I now need to convert them them to ubuntu file system home/tim/sample.pdf.
I cannot type them all in again, and I can’t work out how to do it.
Any help would be greatly appreciated

RFO