You can jump on the Piccadilly line straight to South Kensington (approx 40 mins) or change at Hammersmith or Barons Court for the District line to High St Kensington. Alternatively take the HEX and then the Circle/District line from Paddington to High St Kensington. Monday morning rush hour tube travel isn't pleasant heading into London so I would go for the HEX/tube option.