Amending semanitc models

Hi, 

I've got a report that's working well and data set refreshing nicely. 

I'm trying to use that same dataset for a second report and just created a connection in desktop to get data from semantic model. 

I need to make changes to it though as I'm using different columns and need to change the data type. 

Do I need to open the origional report and amend and republish (seems laborious) or can I amend it quicker elsewhere? 

Many thanks.