Convert PDF to Corel Draw X4

I have read a lot on How to convert a ".PDF" to a ".cdr".  I've tried using the Import function and a routine called "Cool PDF Reader".Both of these work fine if you are converting a "simple" (one idea) drawing. However,my problem is none of these routines do an "un-weld".

To give an example of what I may want to do is: I came across a ".pdf" file that had some artwork designed to be a scroll saw template. I can bring them into Corel Draw and do several things. The art work was a circle that had lettering on the outside curve of the circle. I wanted to change the wording. I went to the Corel Draw menu Arrange>Shaping and brought up the sub-menu. Weld was enabled but UnWeld was not.

Is there any way, any routine that will allow you to un-weld a graphic?

Thanks,

Sam