Does anybody know how to change data series from a histogram/bar representation to a line in a Graph on a Report?

I have 5 measurements I need to follow. I created the report and the queries and then selected the 'Custom' type in the Chart Types option page - this creates a mix of the 5 indicators I need. However, it created a lot of bar indicators and I need to change some to the Line indicators.

I tried right-clicking and going thru all the option areas but can see nothing. Does anyone know ????