Error occurred in deployment step 'Add Solution': A feature with ID '' has already been installed in this farm. Use the force attribute to explicitly re-install the feature.

Hi I am getting the error

Error occurred in deployment step 'Add Solution': A feature with ID 10495515-2482-41fd-98eb-3c87f739f54b has already been installed in this farm.  Use the force attribute to explicitly re-install the feature.

when trying to deploy web parts

question 1 - how do i use the force attribute when deploying from visual studio

question 2 - am i deplying it to the right place, if i deply it to the url:port that points to my central admin tool it deploys but i cant seem to see it in any of my webs in my site collection, if i deploy it to theurl:port that points to my site collection I get this error.

im new to all this by the way :)

thanks in advance