How to smoothens or just keep one top peaks at the left bell/curve for histogram to pdf plots?

1 Original Histogram as follow:

2 I convert to PDF, there're multiple small peaks at the left bell curve (blue color plots) as follow:

I am using interpolations to replot the pdf, but not able to smoothen the curve? How to smoothens or just keep one top peaks at the left bell/curve for histogram to pdf plots?

3. The desired outcome is as follows for the left bell. The plot is smoothen and only plot along the peaks.

Thank you very much.