scales, partial demolition

[MB78]

hello to all, excuse the banality of the question, but as a neophyte I find myself a little dismissed. I modeled an octagonal steel scale, in the restructuring project that concerns it, is expected to eliminate a pawn and consequently of its handrail portion. Is there a way to assign a demolition phase limited to these two portions, so that we can then have a correct comparative table?

thanks in aticipo
mb

 

[gfrank]

you have to draw the two sections of ramp separetamente, like two contigue ramps (two stairs)

 

[MB78]

Thank you so much gfrank!