[MC5C]

To answer the question, the Samick is a 10 watt solid state amp, and there are essentially no modifications you can make to it. It's not like a tube amp where basically anyone can change the circuits around to add features, change tone stacks, change gain characteristics, etc. So what people are suggesting is you add stages before the amp to get any sound you desire, and these can be simple pedals with reverb, delay, distortion, phasers, etc, or they can be "modelers" - quite sophisticated computer based digital devices that can mimic any common amp tone or pedal tone.

The other path suggested is to learn more about tube amps, and find/make a tube amp that suits your needs. Many different ones exists, some easier than others to modify if that ends up being your goal. An awful lot of people these days love little 5 watt tube amps that get rock/overdrive sounds at bedroom volume levels. There is another thread discussing exactly that here right now.

Personally, I bought a modeling pedal that has about 500 preset tones, played with it a bit, and put it away. Then I pulled out an old 1950's hi-fi tube amp and modified it to be a killer guitar amp. I may change it up a bit more this winter if I get bored. The only effect I persistently use is a Boss RV-2 reverb pedal.