I have downloaded the fastq.tgz files for an ENCODE RNA-SEQ data and unpacked the files. The data set is paired end illumina. I am a bit confused, as there are 5 files for read1 and 5 files for read2 for each sample. Am I supposed to merge the 5 files before aligning to the hg19 genome?  

If yes, how should I merge these files?

I would greatly appreciate any help you can provide.

Best regards,