How to change zoom level

I need the constrution zoom level of canon sx280hs

there is a white pieces ,i need to know where is the right place to fix it.

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What do you mean by "there is a white pieces" ?

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I alrady find out the question ,the littel white pieces is a smalle plastic ,it is to fix the zoom level for zoom out or zomm in,it was broken .now I repaire it by myselfe.thanks

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