This is my first tab and its easy. Listen the song and play with it until you can't hear 
guitar anymore than it means you got it. Have fun

Here are the chords:

 F-  x33210       (you can hit the first string for both chords but it sounds
 C-  x32010         better to me if you mute it with a thumb, your choice)
 Am- 002210

During the song you will hear different transition chords so here there are:

This one is from C to Am
e|----------------------------------------------|
B|----------------------------------------------|
G|---------0-------0----------------------------|
D|-------2-------0---0--------------------------|
A|-----3-------2--------------------------------|
E|----------------------------------------------|

This one is from Am to C
e|----------------------------------------------|
B|----------------------------------------------|
G|---------0-----0------------------------------|
D|-------2-----0---0----------------------------|
A|-----0-----2----------------------------------|
E|----------------------------------------------|

This one is at the ends of chorus
e|----------------------------------------------|
B|----------------------------------------------|
G|----------------------------------------------|
D|----------------------------------------------|
A|----------------------------------------------|
E|----0--1--3-----------------------------------|

Intro:  F C  4x

Am
 Ooooooooooooh
C
 ooooooooooooh
              Am
 yea yea yeaa

 ooooooh
         C
 ooooh yea

F
 now you and I
           C
 can get together

 let us start a revolution
F
 change this world
              C
 to what it should be

 and forget all this confusion

F
 we could live together
         C
 for the sake of love

 what are we fighting for
        F
 oooh now
                          C
 we could start heeling today


 if we can just learn to give
Am
 give a lil' love
                              C
 you and I can change the world

 live a lil' love

 make it better if we try
Am
 show a lil' love

 let your love rain
         C
 let it rain down on me

F                         C
 now if we wait and do nothing

 then what about their future
F                          C
 how can we look in to their eyes

 and say we love our children
F
 we can make it better
          C
 feel the love inside

 forget foolish pride

       F
 ooh yea
                             C
 I know that we can find the way

 if we can just learn to give
Am
 give a lil' love

 you and I can change the world
C
 live a lil' love

 make it beter if we try
Am
 show a lil' love

 let your love rain
           C
 let it rain down on me

           F
 so let it rain

 for the people
         C
 let it rain
                    F
 shower me with your love

 let it rain now
         C
 let it rain

 and let the children sing

F
 around the world you feel the love that we say hey
C
 around the world we say make a beter day
F
 around the world we feel the love that we say hey
C
 around the world we say make a beter day
F
 around the world we feel the love that we say hey
C
 around the world we say make a beter day
F
 around the world we feel the love that we say hey
C
 around the world wa say make a beter day


 come on come on come on yea
Am
 give a lil' love

 you and I can change the world
C
 live a lil' love

 we can make it happen
Am
 show a lil' love

 let it rain
         C
 let it rain down on me
          F
 let it rain
C
 so let it rain

 for all the people
         F
 let it rain
             C
 so let it rain

F
 aaaaaaaaaaah
C
 oooooooooooh
F
 aaaaaaaaaaaaah
C
 ooooooooooooh
Am
 aaaaaaaaaaaah
C
 oooooooooooh
Am
 aaaaaaaaaaaaaaah
C
 oooooooooooooh