I have a carbon road bike that I love however it was built for flat and fast which is fine, however I am riding triple bypass in July and would like to get some lower gears for spinning up the long climbs.
I have no trouble riding hills with the current set up however sustaining a 5%+ climb for 20 miles will be tough with this set up.

This is what is currently on the bike:
Front Chainring 53-39
10-speed cassette 11-28

Would it be possible for me to have the cassette changed to a 10-speed cassette 11-32 and front chainrings to 52-36?

I am trying to do this as economically as possible without having to change my rear and front derailers.

Any suggestions or recommendations?

Thanks!