First of all in the MT4 platform go to Tools -> Option click on the tab Charts then change the value of the default Max bars in history and the Max bars in chart to the maximum (click in the editable field and keep pressing the number 9 until it stops), do the same form the other field and press ok. If you open again the tab the number changes outomatically to the max it can support (you see the number change from 9999999999999999 to a new number, this is ok).
Now you must collect the data, go to Tools -> History Center, click on the pair you need (eg. EURUSD) than click on the timeframe bar you want (always click on the 1M timeframe) then push the button download in the bottom.
You have done.
Keep in mind that this is the minimum precision you should have to test your EA.
There is an howto somewhere in the forum that explain how to get the tick data from Dukascopy but for your starting i think this is enough.
Have a good weekend, and if you need help ask again.
Bye to all.
I find it, look here