Excel first row removing

Yes, it is feasible with the Power BI Inferface. 

First please click on Remove top rows and select 1.

Next Use first row as headers:

The effect:

And full M code:

let
    Source = Excel.Workbook(File.Contents("C:\PowerBI.xlsx"), null, true),
    Arkusz1_Sheet = Source{[Item="Arkusz1",Kind="Sheet"]}[Data],
    #"Changed Type" = Table.TransformColumnTypes(Arkusz1_Sheet,{{"Column1", type text}, {"Column2", type text}, {"Column3", type text}, {"Column4", type text}, {"Column5", type text}, {"Column6", type text}, {"Column7", type text}, {"Column8", type text}, {"Column9", type text}, {"Column10", type text}, {"Column11", type text}, {"Column12", type text}}),
    #"Removed Top Rows" = Table.Skip(#"Changed Type",1),
    #"Promoted Headers" = Table.PromoteHeaders(#"Removed Top Rows", [PromoteAllScalars=true]),
    #"Changed Type1" = Table.TransformColumnTypes(#"Promoted Headers",{{"Purchase Date", type text}, {"Type", type text}, {"Trade", type text}, {"GB", type text}, {"Miles", type text}, {"UnLocked", type text}, {"Sell Date", type text}, {" Purchase price ", type text}, {" Sold Price ", type text}, {" Profit ", type text}, {" Net Amount ", type text}, {" Profit(%) ", type text}})
in
    #"Changed Type1"

Hope this helps!

Thanks