Run an SSIS package located on a linked server from a stored procedure I am creating a stored procedure on my First machine named Server1 and 

would like to call an SSIS package named mypackage.dtsx located on my 

Second machine named Server2

Noting that I already linked my Second machine to my First 
machine and I am using SQL Server 2012 

on both of them. How can I accomplish this?
I would recommend creating a SQL Agent job on server 2 then running sp_start_job over the linked server to execute it. That stored proc is documented here. 

If your SSIS package is deployed to SSISDB then you could execute it directly via stored proc if you prefer. See the answer on this question.