DieSse has answered your first question, it is possible to convert them to the lower bit rate using this programme click here its not free, but someone might be able to find a free one for you. Having said that its only $10 or about six quid in real money.
I originally suggested Audacity as I thought most folks are usually interested in a free program.
But there's another versatile program I use, that will also alter MP3 bitrate(kbps) & much more, called dBpowerAmp Music Converter (dMC) click here.
dMC's MP3 encoder & 'Power Pack' is on a 30-day free trial & loses these features at the end of the trial, but one can purchase these for as little as £8 (or $14 click here) & own the complete program. G
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