Sarah,
Thank you for your comments, especially those about 'hinn' and 'goðu' which I genuinely misunderstood. My inappropriate translation of 'vil' however, was pure carelessness.
 
Early retirement probably gives me more leisure than most people to study Old Norse. Consequently I can do 'Boðvar' and still have lots of time to go over Gordon's  'Introduction to Old Norse' again. On re-reading this, I find there are difficult words or phrases for which Gordon provides a translation in his notes, but gives no grammatical or semantic reasons to explain how his interpretation comes about, and often I cannot work out the reasoning behind this. Is there any noble soul out there who has the skill and the time to help me out ?  I wish there was an Open Universiry course on Old Norse!
 
Anyhow, on with the translation:
 
Eigi þorir hann heim at fara heldr. Nú gengr Boðvarr móti dýrinu;
Not dare he home to go on the contrary. Now goes Boðvarr against beast the.
On the other hand, he didn't dare go home.  Now Bothvar moved against the beast
 
þat hœfir honum, at sverðit er fast í umgjörðinni, er hann vildi bregða því.
That befell him, that sword-the is fast in scabbard-the, which he wanted to draw it.
It was just his luck that the sword stuck fast in the scabbard, from which he wanted to draw it.  
 
Boðvarr eggjar nú fast sverðit ok þá bragðar í umgjörðinni, ok nú fær hann brugðit
Bothvar urges now fast sword-the and then stirs in scabbard-the, and now was able moved
Boðvarr now worked to free the sword which was stuck fast, and then he was able to jiggle 
 
umgjörðinni svá at sverðit gengr ór slíðrunum
scabbard-the so that sword-the goes out of sheath-the
the scabbard so that the sword slipped from the sheath.