No matter what you think of the singing, the guitars in this song are very catchy. There are 2 guitars. Here we look at Guitar 1. This plays the main rhythm chords but also does the solo. Whereas Guitar 2 plays the catchy little melody lines throughout the song (we will look at that separately).
The song is easily divided into just a few sections and riffs:
Intro / Verses - Hold the B minor chord and have your volume set low. Strike the chord and gradually raise the volume knob on your guitar to full. Then simply strum B minor - E major repeatedly. Use regular down / upstrokes with no breaks in rhythm (16 strums per chord). This is a large part of the song and very easy to learn. Just keep switching between these 2 chords.
Chorus - This is a short repeating riff. It starts and finishes each time at fret 14 (with about 7 chord position changes inbetween). You need to control the strings here. The trick is to keep your first finger lightly touching the D and G strings throughout to mute them. This means that when strumming, these 2 strings will be drowned out by the notes held by your 1st and 3rd fingers (either side). You can also use your thumb to mute the low strings if you wish.
There are some muted strikes. Just release all pressure on the strings, but keep touching them. Continue strumming to get that funky 'click' sound.
Solo - The solo is quite cool and catchy. It starts off easy enough, but there are some quick hammer / pull offs later on which will take some practice even if you are no beginner.
Verse Variation - This is just using the 2 same chords from the first verse again and palm muting / open striking them. Use downstrokes only here. Watch the ActionTab and you'll see how straightforward this part is.
And that's all you need to know for the main rhythm guitar! Everything else in the song is just repetition of the same chords / riffs.