Surface RT how to open a wps file

Microsoft Word is supposed to be able to open that format but you have to force it to do it and the version of Word that is in the RT is about 98% of the actual x86 based Word used on regular Windows computers and may not have the filter within it.

What you will have to do is convert the files over and you will need to do that with a regular computer.  Microsoft has a converter that you can download from here: http://www.microsoft.com/en-us/download/details.aspx?id=12

The WPS format was originally for Microsoft Word 2000 and later was used in Microsoft Works.  Both are completely defunct now.  A lot of people are still using Works since it came free with a lot of computers still in use today and can't blame anybody for still using it but those people need to "upgrade" because almost nobody can open that file format.

Download the converter to a regular computer and move those WPS files over to it.  Convert them and then move them over to the RT.

DO NOTE: that when convert those files to edit and send back, those people using Microsoft Works will not be able to open it!  A regular "Pandora's Box" situation you have there.