Power Point Vsto

Question

Is it possible, programatically to change equation to normal text in Power Point 2013-2016? And if yes, how? I Managed to locate equations. And my goal is to change change the font of equations. But it won't let me unless i change it to normal text. So my idea was going throug slides, then throug lines in slides, finding text with "Math Cambria" font, then to manipulate it. But font won't change. 

 For Each Slide As PowerPoint.Slide In Presentation.Slides
            For Each Shape As PowerPoint.Shape In Slide.Shapes
                For Each Paragraph As PowerPoint.TextRange In Shape.TextFrame.TextRange
                    For Each Line As PowerPoint.TextRange In Paragraph.Lines
                        If Line.Font.Name = "Cambria Math" Then
                            With Line.Font
                                .Name = "Calibri"
                                .Bold = True
                            End With
                        ElseIf Line.Font.Name = "Calibri" Then
                            With Line.Font
                                .Name = "Palatino"
                            End With
                        End If
                    Next Line
                Next Paragraph
            Next Shape
    Next Slide

I also tried

For Each Window As PowerPoint.DocumentWindow In Windows
            Selection.OMaths(1).ConvertToMathText
   Next Window

I am aware that was supposed to turn it to equation, but i guessed if i could do that i could find a way backwards. But that didn't work aswell.