How to remove items using Jquery from Lookup field with > 20 items

Hi,

I want to remove the items using JQuery from lookup dropdown list which is having greater than 20 items. After removing the items I want to add a subset of items ...six, ten,sixteen . Kindly let me know the

1. syntax of removing the existing lookup and then 

2. syntax to add the subset of items in  the same lookup field .

Lookup fields looks something like this -

<inputname="ctl00$m$g_50e06708_50bb_4560_ab4c_6c3c5a95a113$ctl00$ctl04$ctl01$ctl00$ctl00$ctl04$ctl00$ctl01"
type="text"id="ctl00_m_g_50e06708_50bb_4560_ab4c_6c3c5a95a113_ctl00_ctl04_ctl01_ctl00_ctl00_ctl04_ctl00_ctl01"
class="ms-lookuptypeintextbox"onfocusout="HandleLoseFocus()"opt="_Select"title="Numbers"
optHid="SPNumbers_Hiddenctl00$m$g_50e06708_50bb_4560_ab4c_6c3c5a95a113$ctl00$ctl04$ctl01$ctl00$ctl00$ctl04$ctl00"
onkeypress="HandleChar()"onkeydown="HandleKey()"match=""
choices="(None)|0|eight|8|eightteen|18|eleven|11|fifteeen|15|five|5|four|4|fourteen|14|nine|9|nineteen|19|one|1|seven|7|
seventeen|17|six|6|sixteen|16|ten|10|thirteen|13|three|3|twelve|12|twenty|20|two|2"onchange="HandleChange()"/>