How do you re-assign a geometric reference to a control line

We are in the process of breaking out our compiled alg.dgn file into individual alg.dgn files in efforts to reduce file size and increase processing speed within corridor files. In doing so, we are attempting to re-associate our control lines to their corresponding individual alg.dgn reference files using the replace reference tool under the geometric rules dialog. 

However, what we found is that even after the control line dependency is replaced with the new alg.dgn file, in the properties tab, the original compiled alg.dgn is still listed as a dependency of the control line.  Therefore, if the compiled alg.dgn reference file is detached from the control line.dgn file, then the control lines loses all dependencies.

We are trying to find away to remove the original alg.dgn as a dependency (marked with the red x below) for the control lines so that only the new alg.dgn file is the only reference assosicated with the control line.