How to convert solidworks file into STEP or IGES file...??
It is really simple Shridharan, see below.
Answered with a tutorial: https://grabcad.com/tutorials/how-to-convert-solidworks-file-into-step-or-iges-file
Some advice regarding saving files from solidworks.
Iges and Step are great, but consider parasolid (XT) - I have just tested, an 8.6 meg solidworks file as Iges come out at 6.5 meg and as parasolid 1.33 meg - GrabCAD we should have a parasolid option, this makes sense for upload/download and server space, best option for email as well - most solid modellers will open parasolid.
Also with feature based modelling - if you need to email or upload data try rolling back to the origin in the tree, all features suppressed, the same file at 8.6 meg with features suppressed come in at 3.9 meg.
Use GrabCAD Workbench. Upload you sldprt file to workbench then you can right click on the uploaded file and select "download as". You can download the file in the format of STEP, IGES, STL, Parasolid, ACIS, JT, or VRML.
If your still struggling I'd advise you to check out my tutorial for converting files in Workbench
How to convert CAD files in Workbench